Effect of the amount of cold work (CW) on corrosion of Type 304 nuclear grade stainless steel in high-temperature water was investigated. The investigation was conducted by comparing the microstructure of oxide scales formed on the steel subjected to different amounts of CW. The result revealed that increasing the amount of CW resulted in inhomogeneous thickness of the inner continuous oxide film, which was caused by the enhanced localized corrosion at the deformation band (DB) and the grain boundary (GB). Further, the localized corrosion rate at the DB was likely higher than that at the GB, which resulted from the difference in the composition of the oxide formed at the DB and GB.